Increasing of the productivity of old-aged lavender plantation

In the conditions of a submountain zone of the Northern Caucasus, the first signs of aging of lavender bushes are usually seen in 7-8 years after foundation of the plantations. At the same time old-aged plants loose the frost and winter hardiness, yields of inflorescences and essential oil are reduced. The most effective ways to restore the annual growth of new substituting shoots and increasing the productivity of old-aged lavender bushes are different ways of rejuvenating trimming. The researches were conducted in 2013-2014 in the submountain zone of the Northern Caucasus in Voznesensky branch of VNIIMK on plantations of Lavandula angustifolia planted in autumn of 2006. The four dates (February, July, October and November) and two ways of bushes trimming (on the "black leg" (2 cm cutting height) and 10 cm height from the soil surface were studied. The best way of rejuvenating trimming of Lavandula angustifolia guarantying the formation of the maximal number of new substituting shoots is trimming to a height of 2 cm from the soil surface, also known as trimming on the "black leg". The same method of trimming provides the maximal increase in inflorescences yield from the rejuvenated old-aged lavender plants up to 4 t per ha and essential oil yield up to 35 kg per ha. Best time for both methods of trimming is November and February, when the regrowth of new substituting shoots on the old-aged lavender plants occurs at the beginning of spring.